The common-law doctrine of incompatibility also constrains many
instances of dual office holding. The original case on the subject in
Texas, Thomas v. Abernathy County Line Indep. School Dist., 290 S.W. 152
(Tex. Comm'n App.-- 1927, judgm't adopted), held that one individual
could not simultaneously hold the offices of city alderman and school
trustee of a district which had overlapping boundaries with the city.
This office has used the "conflicting loyalties" type of incompatibility
on many occasions to bar various examples of dual office holding.
[Footnote 1] See, eg., Attorney General Opinions
JM-634 (1987)
(offices
of city alderman and school district trustee are incompatible);
JM-133
(offices of county auditor and city council member are incompatible,
where jurisdictional boundaries overlap),
JM-129 (1984)
(offices of
community college trustee and county commissioner, where jurisdictional
boundaries overlap, are incompatible).

In Attorney General Letter Opinion No.
90-18 (1990),
this office
said that incompatibility barred a person from serving both as a city
council member and a board member of a water district, where it was
indicated that a contract between the two entities was likely. In the
situation you pose, the school district is already under contract with
Smith County for the tax assessor-collector to assess and collect school
district taxes. In such an instance, where a contract between two
governmental bodies is extant and expected to continue, we believe that
the doctrine of incompatibility bars a single individual from serving
both. As a result, we conclude that one person may not simultaneously
hold the position of county tax assessor-collector and member of the
board of trustees of a school district which contracts with the county
to assess and collect its taxes.

It is well established that when a person qualifies for and accepts
a second office which is incompatible with another office which the
person holds, he ipso facto relinquishes the first. See Attorney
General Opinion
JM-133;
Attorney General Letter Opinion No.
90-23 (1990).
Article XVI, section 65 of the Texas Constitution provides that
"automatic resignation" will occur in the first office upon one's
becoming a candidate for a second office only if more than one year
remains on the unexpired term of the first office. Since you indicate
that the tax assessor-collector's current term will expire at the end of
1992, he will not automatically resign the office of tax
assessor-collector by becoming a candidate for school board trustee during 1992.
We caution, however, that acceptance of the office of school board
trustee would cause him to automatically resign his position as county
tax assessor-collector.

Yours very truly,

Rick Gilpin
Assistant Attorney General
Opinion Committee

Footnotes

[Footnote 1] The other kind of incompatibility, often deemed "self-employment," prohibits one person from occupying any position which has supervisory authority over another position which he holds. For a classic example, see Attorney General Letter Advisory No.
114 (1975) (individual may not simultaneously hold positions of school board
trustee and teacher in same district).